SI base unit for the electric current (symbol: A). The ampere is that constant
current which, if maintained in two straight parallel conductors of infinite
length, of negligible circular cross-section, and placed 1 metre apart in
vacuum, would produce between these conductors a force equal to 2 × 10–7
newton per metre of length (9th CGPM, 1948).
G.B. 70; 1996, 68, 961
IUPAC Compendium of Chemical Terminology
2nd Edition (1997)